Multiple-fuse plug



March 4,1924. 1,485,636

J. F. SKINNER MULT I PLE FUSE PLUG Filed Jan. 5, 1921 Jo/rh I'd/fame).

Patented Mar. 4, 1924.

UNITED STATES PATENT OFFICE.

I MULTIPLE-FUSE PLUG.-

Application filed January 5, 1921. Serial No. 435,214.

To all whom it may concern:

Be it known that 1, JOHN F. SKINNER, a citizen of the United States, residing at Detroit, in the countyof l'Va-yne and State of Michigan, have invented a new and useful Multiple-Fuse Plug, of which the following is a specification;

-This invention relates to multiple fuse plugs, and more particularly to such fuse plugs as are provided with a'pivotal con-- tact member adapted to be rotated to successively engage a circular series of fuse terminals.

The object of the invention is to provide a fuse plug, of the character described, of an inexpensive construction, adapted to be quickly assembled, securing a very positive contact of the rotative contact member with the various fuse terminals, and providing for a very abrupt and positive snap movement of said rotative member into its several positions of use so that anyappreciable arcing may be avoided.

The invention consists in various structural features, including the formation of the rotative contact member integral with one of the terminal contacts of the plug, the use of said element to maintain the assembled relation of the fixed and rotative insulating portions of the plug, the formation of the several fuses integrally, and in a novel mounting of the fuse forming member in the plug.

A preferred embodiment of the invention is hereinafter described and illustrated in the accompanying drawings, wherein, b

1Fig. 1 is a side view of the improved p .ug,

Fig. 2 is an end view of the same.

Fig. 3 is an axial sectional View of the same, taken upon the line 83 of Fig. 2.

Fig. 4 is a cross section view taken on line 44 of Fig. 3. I

Fig. 5 is an" end view of the "fuse-carrying member of the plug.

Fig. 6 is a cross-section on line 66 of Fig. 3.

Fig. 7 is a detail side view of the fuse forming element. 7

In these views the reference character 1 designates the stationary fuse carrying insulating member vof'the plug, and 2 a rotative insulating member thereof, the latter member being mounted within the former. It is preferred to form the member 1 with an opening therethrough from end to end,

said opening receiving the member 2 and forming a fuse chamber 3 in the larger end of said member, the intermediate portion 4: of said opening being of lesser diameter than said chamber, and the other end portion 5 of the opening being still further reduced. The rotative member 2 has portions varying in diameter, corresponding to and respectively located in the portions 3, at and 5 of said opening, and further has a rim portion 6 adapted to seat upon the larger end of the member 1 and cover a circular series offuse members 7 which are peripherally disposed within the chamber 3, the wall of said chamber being longitudinally'channeled as indicated at 8 to accommodate the fuse members. The larger end portion of the member 2 is formed with a chamber 9 and with an opening 10 through the wall of said chamber, and a spring contact member 11 is disposed-within said chamber with its free end portion projecting through the opening 10 to be engaged selectively with said fuse members, as is best shown in Fig. 1. The fuse members 7 project integrally upward from a ring 12, said parts being preferably stamped from a strip of sheet-metal, the stamping being then rolled to the desired annular form. The ring 12 is proportioned to snugly change the direction of their width from circumferential to radial. Through being thus twisted they are brought to bear against radial faces of the channels 8. Adjacent its upper end each fuse member is formed with an integral lug 15 which is bent against the peripheral wall of the chamber 3, as is best seen in Fig. 4, formingcontact elements'adapted to be engaged by therotative spring contact arm 11. Said arm forms an arcuate curve and is adapted, when tensioned by a predetermined rotation of the member 2 in the direction of the arrow (Fig;

4) to snap from engagement with any of the contact elements 15 into contact with the next element of the series. The arm 11 is formed by the end portion of a metal strip having a doubled portion 16 bearing upon the bottom of the chamber 9, a portion 17 passing centrally through the member 2, longitudinally thereof, anda doubled por tion 18 bearing against the small end of the member 2 and projecting outwardly somewhat beyond said end to bear also upon the corresponding end of the member 1. The portion 18 of said strip forms one of the terminal contacts of the plug and further retains the member 2 rotatively engaged with the member 1. The other terminal contact of the plug is formed, as is common practice, by a sleeve 19 embracing-the smaller end portion of the member 1 and shaped to form screw threads adapting the plug for engagement with a welLknown type of socket receptacle.

Intermediate the ends of the inner insulatin member 2, a detentpin 20 is diametrically inserted in said element, said pin having a projecting bent end portion 2i which bears resiliently against the wall of the opening 4 and prevents any reverse rotation of the member 2. Thus the contact arm can be rotated only in such a direction as will'place it under the tension neccs-- sary to secure a snap travel of said arm from one to another of the contact elements 15. Also it is made impossible to so shift the arm as to return it to engagement with a previously used burned-out fuse. A disk 22 of mica or other insulating material is so mounted upon the member 2 as to provide a cover for the chamber 9. To assist in maintaining the proper positions of the fuse members 7 the large end of the memher 1 may be circumferentially grooved between the channels 8, as indicated at 23, and the upper ends of the fuse members 6 may be bent and pressed snugly into said channels, as shown at 2st.

It is a desirable feature of the described plug that the parts thereof are adapted to be produced at low cost, and may be quicklyassembled without the use of solder and with the exercise of very little'skill.

\Vhat I claim is: j i

1. A multiple fuse plug comprising two relatively rotative insulating members, one having an opening extending from end to end, and the other being disposed within said opening, a series of fuses and correspondmg contact elements carried by .the

outer member, a commonterminal foisaid fuses carried by said member, a companion terminal carried by the inner insulating member, at one end thereon, the other end of said inner member having a chamber openrelatively rotative insulating members, one

having an opening extending from end to end, and the other being disposed within said opening, a series of fuses and corresponding contact elements carried by the outer member, a common terminal for said fuses carried by said member. a second terminal carried by the inner insulating member, and a conductor carried by the,

inner insula ing member forming at one end thereof a spring contact arm consecutively engageable with said fuse contact elements upon relative rotation of the two insulating members, and forming at the other end of said inner member/said second terminal for the plug, said conductor maintaining the two insulating members rotatively engaged. 3. A multiple fuse plug, comprising two insulating members, one having a chainbered portion rotatively fitting within the other, a series of fuses carried by the outer insulating member, a terminal for the plug electrically connected to all of said fuses, a series of contact elements for said fuses arranged within the outer andvaround the inner insu ating member, a spring contact arm within said chamber of the inner insulating member and projecting from said chamber to consecutively engage said contact elements upon relative rotation of the two members, and a second terminal for the plug electrically connected to said contact arm; I

4. A multiple fuse plug, comprising an insulating member, a contact armrotativc. within said member, a series of fuses car'- ried by said'member, contact elements for said fuses consecutively engageable by said arm upon rotationthereof, a ring integral with said fuses embracing the insulating member, a sleeve forming a terminal for the plug embracing the insulating member and bearing upon' said ring, and a second terminal for the plug connected to said contact arm.

In testimony whereof I sign this specification.

JOHN F. SKINNER. 

